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Encyclopedia > Car handling

Car handling and vehicle handling is a description of the way wheeled vehicles perform transverse to their direction of motion, particularly during cornering and swerving. It also includes their stability when moving in a straight line. Handling and braking are the major components of a vehicle's "active" safety. The maximum lateral acceleration is sometimes discussed separately as "road holding". Handling is an esoteric performance area because rapid and violent manoeuvres are often only used in unforeseen circumstances. (This discussion is directed at road vehicles with at least three wheels, but some of it may apply to other ground vehicles.)


Cars, for use on public roads, whose engineering requirements emphasize handling above passenger space and comfort, are called sports cars. 1963 Jaguar E-Type, a classic sports car 1963 Chevrolet Corvette was based upon European sports cars A sports car is an automobile designed for performance driving. ...

Contents

Factors that affect a car's handling

Driver

Handling is a property of the car, but different characteristics will work well with different drivers.


Familiarity

A person learns to control a car much as he learns to control his body, so the more he has driven a car or type of car the better it will handle for him. One needs to take extra care for the first few months after buying a car, especially if it differs in design from those he is used to. Other things that a driver must adjust to include changes in tires, tire pressures and load. That is, handling is not just good or bad; it is also the same or different.


Weather

Weather affects handling by making the road slippery. Different tires do best in different weather. Deep water is an exception to the rule that wider tires improve road holding. (See aquaplaning under tires, below.) Firestone tire This article is about pneumatic tires. ...


Road condition

Cars with relatively soft suspension and with low unsprung weight are least affected by uneven surfaces, while on flat smooth surfaces the stiffer the better. Unexpected water, ice, oil, etc. are hazards.


Weight distribution

Main article: Weight distribution

Weight distribution refers to the apportioning of weight within a vehicle, but is used most often to refer to cars, airplanes, and watercraft. ...

Center of gravity height

The center of gravity height, relative to the track, determines load transfer, (related to, but not exactly weight transfer), from side to side and causes body lean. Centrifugal force acts at the center of gravity to lean the car toward the outside of the curve, increasing downward force on the outside tires. This article or section may contain original research or unverified claims. ... In automobiles, load transfer is the imaginary shifting of weight around a motor vehicle during acceleration (both longitudinal and lateral). ... In automobiles, weight transfer (often confused with load transfer) refers to the redistribution of weight supported by each tire during acceleration (both longitudinal and lateral). ...


The center of gravity height, relative to the wheelbase, determines load transfer between front and rear. The car's momentum acts at its center of gravity to tilt the car forward or backward, respectively during braking and acceleration. Since it is only the downward force that changes and not the location of the center of gravity, the effect on over/under steer is opposite to that of an actual change in the center of gravity. When a car is braking, the downward load on the front tires increases and that on the rear decreases, with corresponding change in their ability to take sideways load, causing oversteer. Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ...


Lower center of gravity is the principle performance advantage of sports cars, compared to sedans and (especially) SUVs. Some cars have light materials in their roofs, partly for this reason. It is also part of the reason that traditional sports cars are open or convertible. 1963 Jaguar E-Type, a classic sports car 1963 Chevrolet Corvette was based upon European sports cars A sports car is an automobile designed for performance driving. ... This article or section may be confusing or unclear for some readers, and should be edited to rectify this. ...


Body lean can also be controlled by the springs, anti-roll bars or the roll center heights. A sway bar (also called an anti-sway bar or anti-roll bar) is an automobile suspension device. ... The roll center of a vehicle is the notional point at which the cornering forces in the suspension are reacted to the vehicle body. ...


Center of gravity forward or back

In steady-state cornering, front heavy cars tend to understeer and rear heavy cars to oversteer, all other things being equal. The mid-engine design offers the ideal center of gravity. Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... Mid-engine in a Hanomag-Fahrgestell. ...


When all four wheels and tires are of equal size, as is most often the case with passenger cars, a weight distribution close to "50/50" (i.e. the center of mass is mid-way between the front and rear axles) produces the preferred handling compromise. In physics, the center of mass of a system of particles is a specific point at which, for many purposes, the systems mass behaves as if it were concentrated. ...


The rearward weight bias preferred by sports and racing cars results from handling effects during the transition from straight-ahead to cornering. During corner entry the front tires, in addition to generating part of the lateral force required to accelerate the car's center of mass into the turn, also generate a torque about the car's vertical axis that starts the car rotating into the turn. However, the lateral force being generated by the rear tires is acting in the opposite torsional sense, trying to rotate the car out of the turn. For this reason, a car with "50/50" weight distribution will understeer on initial corner entry. To avoid this problem, sports and racing cars often have a more rearward weight distribution. In the case of pure racing cars, this is typically between "45/55" and "40/60." This gives the front tires an advantage in overcoming the car's moment of inertia (yaw angular inertia), thus reducing corner-entry understeer. In physics, the center of mass of a system of particles is a specific point at which, for many purposes, the systems mass behaves as if it were concentrated. ... Moment of inertia, also called mass moment of inertia and, sometimes, the angular mass, (SI units kg m2, Former British units slug ft2), is the rotational analog of mass. ...


Using wheels and tires of different sizes (proportional to the weight carried by each end) is a lever automakers can use to fine tune the resulting over/understeer characteristics. Once a car is designed, weight distribution can be changed by using different diameter tires or jacking the car up higher or lower at the suspension springs. Jacking is frequently done with screws or shims at the springs.


Roll angular inertia

This increases the time it takes to settle down and follow the steering. It depends on the (square of the) height and width, and (for a uniform mass distribution) can be approximately calculated by the equation: I = M(height2 + width2) / 12.


Greater width, then, though it counteracts center of gravity height, hurts handling by increasing angular inertia. Some high performance cars have light materials in their fenders and roofs partly for this reason.


Yaw and pitch angular inertia (polar moment)

Unless the vehicle is very short, compared to its height or width, these are about equal. Angular inertia determines the rotational inertia of an object for a given rate of rotation. The yaw angular inertia tends to keep the direction the car is pointing changing at a constant rate. This makes it slower to swerve or go into a tight curve, and it also makes it slower to turn straight again. The pitch angular inertia detracts from the ability of the suspension to keep front and back tire loadings constant on uneven surfaces and therefore contributes to bump steer. Angular inertia is an integral over the square of the distance from the center of gravity, so it favors small cars even though the lever arms (wheelbase and track) also increase with scale. (Since cars have reasonable symmetrical shapes, the off-diagonal terms of the angular inertia tensor can usually be ignored.) Mass near the ends of a car can be avoided, without re-designing it to be shorter, by the use of light materials for bumpers and fenders or by deleting them entirely. Moment of inertia, also called mass moment of inertia and, sometimes, the angular mass, (SI units kg m2, Former British units slug ft2), is the rotational analog of mass. ... Increasing the mass increases the rotational inertia of an object. ... The word yaw can refer to: Yaw, the name for the Levantine god of chaos, rivers, the sea, and tempests; Yaw, an aeronautical and nautical term which indicates how far a craft is pointing away from its direction of travel due to rotation about its vertical axis. ... Flight dynamics is the study of orientation of air and space vehicles and how to control the critical flight parameters, typically named pitch, roll and yaw. ... In mathematics, a tensor is (in an informal sense) a generalized linear quantity or geometrical entity that can be expressed as a multi-dimensional array relative to a choice of basis; however, as an object in and of itself, a tensor is independent of any chosen frame of reference. ...


Suspension

Automobile suspensions have many variable characteristics, which are generally different in the front and rear and all of which affect handling. Some of these are: spring rate, damping, straight ahead camber angle, camber change with wheel travel, roll center height and the flexibility and vibration modes of the suspension elements. Suspension also affects unsprung weight. The front suspension components of a Ford Model T. Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. ... The rate of a spring is the change in the force it exerts, divided by the change in deflection of the spring. ... A wheel with a negative camber angle Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. ...


Many cars have suspension that connects the wheels on the two sides, either by a sway bar and/or by a solid axle. The Citroën 2CV has interaction between the front and rear suspension. sway bar (also stabilizer bar, anti-sway bar, roll bar, or anti-roll bar, ARB) is an automobile suspension device. ... First generation Ripple Bonnet Citroën 2CV built from 1948 to 1960 The Citroën 2CV (French: deux chevaux, literally two horses, from the tax horsepower rating) was an economy car produced by the French automaker Citroën from 1948 to 1990. ...


The flexing of the frame interacts with the suspension. (See below.)


Tires and wheels

In general, larger tires, softer rubber, higher hysteresis rubber and stiffer cord configurations increase road holding and improve handling. On most types of poor surfaces, large diameter wheels perform better than lower wider wheels. The fact that larger tires, relative to weight, stick better is the main reason that front heavy cars tend to understeer and rear heavy to oversteer. The depth of tread remaining greatly affects aquaplaning (riding over deep water without reaching the road surface). Increasing tire pressures reduces their slip angle, but (for given road conditions and loading) there is an optimum pressure for road holding. Firestone tire This article is about pneumatic tires. ... This does not cite any references or sources. ... A system with hysteresis exhibits path-dependence, or rate-independent memory. Consider a deterministic system with no hysteresis and no dynamics. ... For other uses, see Wheel (disambiguation). ...


Track and wheelbase

The track provides the resistance to sideways weight transfer and body lean. The wheelbase provides resistance to front/back weight transfer and to pitch angular inertia, and provides the torque lever arm to rotate the car when swerving. The wheelbase, however, is less important than angular inertia (polar moment) to the vehicle's ability to swerve quickly.


Unsprung weight

Ignoring the flexing of other components, a car can be modeled as the sprung weight, carried by the springs, carried by the unsprung weight, carried by the tires, carried by the road. Without the unsprung weight, the force of a tire on the road would come from the vehicle weight and motion, transmitted by the spring. But the unsprung weight is cushioned from uneven road surfaces only by the springiness of the tires (and wire wheels if fitted). To aggravate this (for fuel economy and to avoid overheating at high speed) tires have limited internal damping. So the "wheel bounce" or resonant motion of the unsprung weight moving up and down on the springiness of the tire is only poorly damped, mainly by the dampers or Shock absorbers of the suspension. For these reasons, high unsprung weight reduces road holding and increases unpredictable changes in direction on rough surfaces (as well as degrading ride comfort and increasing mechanical loads). Image File history File links original diagram GNU Free Documentation License File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... This does not cite its references or sources. ... Fuel efficiency, sometimes also referred to as fuel economy and commonly gas mileage in the United States, is a numeric measure often used to describe the amount of fuel consumed with regard to the distance travelled in a transportation vehicle, such as an automobile. ... Gasfilled Shock absorber. ... Ride quality refers to the degree of protection offered vehicle occupants from uneven elements in the road surface, or the terrain if driving off-road. ...


This unsprung weight includes the wheels and tires, usually the brakes, plus some percentage of the suspension, depending on how much of the suspension moves with the body and how much with the wheels; for instance a solid axle is completely unsprung. The main factors that improve unsprung weight are a sprung differential (as opposed to live axle) and inboard brakes. (The De Dion tube suspension operates much as a live axle does, but represents an improvement because it is lighter, thereby reducing the unsprung weight.) Aluminium wheels also help. Magnesium alloy wheels are even lighter but corrode easily. This article needs additional references or sources for verification. ... A live axle is a type of beam axle suspension system that uses the driveshafts that transmit power to the wheels to connect the wheels laterally so that they move together as a unit. ... An inboard braking system is an automobile technology where the brakes are not located in the wheels, as is common today, but instead near the differential. ... A de Dion tube is an automobile suspension technology. ... Aluminum redirects here. ... Magnesium alloy wheels, or mag wheels, are sometimes used on racing cars, in place of heavier steel or aluminium wheels, for better performance. ...


Since only the brakes on the driving wheels can easily be inboard, the Citroën 2CV had additional dampers on its rear wheel hubs to damp only wheel bounce. First generation Ripple Bonnet Citroën 2CV built from 1948 to 1960 The Citroën 2CV (French: deux chevaux, literally two horses, from the tax horsepower rating) was an economy car produced by the French automaker Citroën from 1948 to 1990. ...


Aerodynamics

Aerodynamic forces are generally proportional to the square of the air speed, therefore car aerodynamics become rapidly more important as speed increases. Like darts, aeroplanes, etc., cars can be stabilised by fins and other rear aerodynamic devices. However, in addition to this cars also use downforce or "negative lift" to improve road holding. This is prominent on many types of racing cars, but is also used on most passenger cars to some degree, if only to counteract the tendency for the car to otherwise produce positive lift. Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ...


In addition to providing increased adhesion, car aerodynamics are frequently designed to compensate for the inherent increase in oversteer as cornering speed increases. When a car corners, it must rotate about its vertical axis as well as translate its center of mass in an arch. However, in a tight-radius (lower speed) corner the angular velocity of the car is high, while in a longer-radius (higher speed) corner the angular velocity is much lower. Therefore, the front tires have a more difficult time overcoming the car's moment of inertia during corner entry at low speed, and much less difficulty as the cornering speed increases. So the natural tendency of any car is to understeer on entry to low-speed corners and oversteer on entry to high-speed corners. To compensate for this unavoidable effect, car designers often bias the car's handling toward less corner-entry understeer (such as by lowering the front roll center), and add rearward bias to the aerodynamic downforce to compensate in higher-speed corners. The rearward aerodynamic bias may be achieved by an airfoil or "spoiler" mounted near the rear of the car, but a useful effect can also be achieved by careful shaping of the body as a whole, particularly the aft areas In physics, the center of mass of a system of particles is a specific point at which, for many purposes, the systems mass behaves as if it were concentrated. ... Angular velocity describes the speed of rotation and the orientation of the instantaneous axis about which the rotation occurs. ... Angular velocity describes the speed of rotation and the orientation of the instantaneous axis about which the rotation occurs. ... Moment of inertia, also called mass moment of inertia and, sometimes, the angular mass, (SI units kg m2, Former British units slug ft2), is the rotational analog of mass. ... The roll center of a vehicle is the notional point at which the cornering forces in the suspension are reacted to the vehicle body. ...


Delivery of power to the wheels and brakes

The coefficient of friction of rubber on the road limits the magnitude of the vector sum of the transverse and longitudinal force. So the driven wheels or those supplying the most braking tend to slip sideways. This phenomenon is often explained by use of the circle of forces model. This article needs additional references or sources for verification. ... The Circle of Forces is a useful way to think about the dynamic interaction between the tyres of a vehicle and the road surface. ...


One reason that sports cars are usually rear wheel drive is that power induced oversteer is useful, to a skilled driver, for tight curves. The weight transfer under acceleration has the opposite effect and either may dominate, depending on the conditions. Inducing understeer by applying power in a front wheel drive car is useful via proper use of "Left-foot braking." In any case, this is not an important safety issue, because power is not normally used in emergency situations. Using low gears down steep hills may cause some oversteer. Left-foot braking is the technique of using the left foot to operate the brake pedal in a car, leaving the right foot dedicated to the accelerator pedal. ...


The effect of braking on handling is complicated by load transfer, which is proportional to the (negative) acceleration times the ratio of the center of gravity height to the wheelbase. The difficulty is that the acceleration at the limit of adhesion depends on the road surface, so with the same ratio of front to back braking force, a car will understeer under braking on slick surfaces and oversteer under hard braking on solid surfaces. Most modern cars combat this by varying the distribution of braking in some way. This is important with a high center of gravity, but it is also done on low center of gravity cars, from which a higher level of performance is expected. In automobiles, load transfer is the imaginary shifting of weight around a motor vehicle during acceleration (both longitudinal and lateral). ...


Position and support for the driver

Having to take up "g forces" in his/her arms interferes with a driver's precise steering. In a similar manner, a lack of support for the seating position of the driver may cause them to move around as the car undergoes rapid acceleration (through cornering, taking off or braking). This interferes with precise control inputs, making the car more difficult to control.


Being able to reach the controls easily is also an important consideration, especially if a car is being driven hard.


In some circumstances, good support may allow a driver to retain some control, even after a minor accident or after the first stage of an accident.


Steering

Depending on the driver, steering force and transmission of road forces back to the steering wheel and the steering ratio of turns of the steering wheel to turns of the road wheels affect control and awareness. Play — free rotation of the steering wheel before the wheels rotate — is a common problem, especially in older model and worn cars. Another is friction. Rack and pinion steering is generally considered the best type of mechanism for control effectiveness. The linkage also contributes play and friction. Caster — offset of the steering axis from the contact patch — provides some of the self-centering tendency. Steering is the term applied to the collection of components, linkages, etc. ... Steering ratio refers to the ratio betweeen the turn of the steering wheel or handlebars and the turn of the wheels. ... Rack and pinion animation A rack and pinion is a pair of gears which convert rotational motion into linear motion. ... Contact patch is the name applied to the area of a vehicles tire that is in contact with the road surface. ...


Precision of the steering is particularly important on ice or hard packed snow where the slip angle at the limit of adhesion is smaller than on dry roads.


The steering effort depends on the downward force on the steering tires and on the radius of the contact patch. So for constant tire pressure, it goes like the 1.5 power of the vehicle's weight. The driver's ability to exert torque on the wheel scales similarly with her size. The wheels must be rotated farther on a longer car to turn with a given radius. Power steering reduces the required force at the expense of feel. It is useful, mostly in parking, when the weight of a front-heavy vehicle exceeds about ten or fifteen times the driver's weight, for physically impaired drivers and when there is much friction in the steering mechanism. Power steering is a system for reducing the steering effort on cars by using an external power source to assist in turning the wheels. ...


Four-wheel steering has begun to be used on road cars (Some WW II reconnaissance vehicles had it). It relieves the effect of angular inertia by starting the whole car moving before it rotates toward the desired direction. It can also be used, in the other direction, to reduce the turning radius. Some cars will do one or the other, depending on the speed. Steering is the term applied to the collection of components, linkages, etc. ...


Steering geometry changes due to bumps in the road may cause the front wheels to steer in a different directions together or independent of each other. The steering linkage should be designed to minimise this effect.


Suspension travel

The severe handling vice of the TR3 and related cars was caused by running out of suspension travel. (See below.) Other vehicles will run out of suspension travel with some combination of bumps and turns, with similarly catastrophic effect. Excessively modified cars also may encounter this problem. Triumph TR2 The Triumph TR3B was produced by the Triumph Motor Company (Standard Motor Company) in 1962. ...


Electronic stability control

Since automobile safety is mainly a control issue, one should expect a largely electronic solution. Apparently there has already been some advance in this direction. Electronic Stability Control (ESC) is the generic term for systems designed to improve a vehicles handling, particularly at the limits where the driver might lose control of the vehicle. ...


On the other hand, since stability control works by reducing sudden manoeuvres, until the electronics helps to detect the danger sooner, it can never take the place of a low center of gravity, which provides both stability and fast avoidance. (See Wireless vehicle safety communications.) Wireless vehicle safety communications is a possible aid to car safety and road safety. ...


The stability control of some cars may not be compatible with some driving techniques, such as power induced over-steer. It is therefore, at least from a sporting point of view, preferable that it can be disabled.


Alignment of the wheels

Of course things should be the same, left and right. Camber affects steering because a tire generates a force towards the side that the top is leaning towards. This is called camber thrust.


Rigidity of the frame

The frame may flex with load, especially twisting on bumps. Rigidity is considered to help handling. At least it simplifies the suspension engineers work. Some cars, such as the Mercedes-Benz 300SL have had high doors to allow a stiffer frame. 1955 Mercedes-Benz 300SL Gullwing Coupe from the Ralph Lauren collection 1955 Mercedes-Benz 300SL Gullwing Coupe from the Ralph Lauren collection Wikimedia Commons has media related to: Category:1955 Mercedes-Benz 300SL Gullwing Coupe The Mercedes-Benz 300SL was available as a two-seat closed sports car with characteristic...


Common handling problems

When any wheel leaves contact with the road there is a change in handling, so the suspension should keep all four (or three) wheels on the road in spite of hard cornering, swerving and bumps in the road. It is very important for handling, as well as other reasons, not to run out of suspension travel and "bottom" or "top".


It is usually most desirable to have the car adjusted for a small amount of understeer, so that it responds predictably to a turn of the steering wheel and the rear wheels have a smaller slip angle than the front wheels. However this may not be achievable for all loading, road and weather conditions, speed ranges, or while turning under acceleration or braking. Ideally, a car should carry passengers and baggage near its center of gravity and have similar tire loading, camber angle and roll stiffness in front and back to minimise the variation in handling characteristics. A driver can learn to deal with excessive oversteer or understeer, but not if it varies greatly in a short period of time. In auto racing, the racing setup or car setup is the set of adjustments made to the vehicle in order to optimize its behaviour (performance, handling, reliability, etc. ... Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... A wheel with a negative camber angle Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. ...


The most important common handling failings are;

  • Understeer - the front wheels tend to crawl slightly or even slip and drift towards the outside of the turn. The driver can compensate by turning a little more tightly, but road-holding is reduced, the car's behaviour is less predictable and the tires are liable to wear more quickly.
  • Oversteer - the rear wheels tend to crawl or slip towards the outside of the turn more than the front. The driver must correct by steering away from the corner, otherwise the car is liable to spin, if pushed to its limit. Oversteer is sometimes useful, to assist in steering, especially if it occurs only when the driver chooses it by applying power.
  • Bump steer – Is the effect of irregularity of a road surface on the angle or motion of a car. It may be the result of the kinematic motion of the suspension rising or falling, causing toe-in or toe-out at the loaded wheel, ultimately affecting the yaw angle (heading) of the car. This will always happen under some conditions but depends on suspension, steering linkage, unsprung weight, angular inertia, differential type, frame rigidity, tires and tire pressures. If suspension travel is exhausted the wheel either bottoms or loses contact with the road. As with hard turning on flat roads, it is better if the wheel picks up by the spring reaching its neutral shape, rather than by suddenly contacting a limiting structure of the suspension.
  • Body roll - the car leans towards the outside of the curve. This interferes with the driver's control, because he must wait for the car to finish leaning before he can fully judge the effect of his steering change. It also adds to the delay before the car moves in the desired direction.
  • Weight transfer - the wheels on the outside of a curve are more heavily loaded than those on the inside. This tends to overload the tires on the outside and therefore reduce road holding. Weight transfer (sum of front and back), in steady cornering, is determined by the ratio of the height of a car's center of gravity to its track. Differences between the weight transfer in front and back are determined by the relative roll stiffness and contribute to the over or under-steer characteristics.
    • When the weight transfer equals half the vehicle's loaded weight, it will start to roll over. This can be avoided by manually or automatically reducing the turn rate, but this causes further reduction in road-holding. (A collision may be preferable to a rollover.)
  • Slow response - sideways acceleration does not start immediately when the steering is turned and may not stop immediately when it is returned to center. This is partly caused by body roll. Other causes include tires with high slip angle, and yaw and roll angular inertia. Roll angular inertia aggravates body roll by delaying it. Soft tires aggravate yaw angular inertia by waiting for the car to reach their slip angle before turning the car.

Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... Body roll is a reference to the weight transfer of a car towards the outside of a turn. ... In automobiles, weight transfer (often confused with load transfer) refers to the redistribution of weight supported by each tire during acceleration (both longitudinal and lateral). ... A rollover in Sydney, Australia on Christmas day, 2001. ...

Compromises

Ride quality and handling have always been a compromise - technology has over time allowed automakers to combine more of both features in the same vehicle. High levels of comfort are difficult to reconcile with a low center of gravity, body roll resistance, low angular inertia, support for the driver, steering feel and other characteristics that make a car handle well. Ride quality refers to the degree of protection offered vehicle occupants from uneven elements in the road surface, or the terrain if driving off-road. ...


For ordinary production cars, manufactures err towards deliberate understeer as this is safer for inexperienced or inattentive drivers than is oversteer. Other compromises involve comfort and utility, such as preference for a softer smoother ride or more seating capacity.


Inboard brakes improve both handling and comfort but take up space and are harder to cool. Large engines tend to make cars front or rear heavy. In tires, fuel economy, staying cool at high speeds, ride comfort and long wear all tend to conflict with road holding, while wet, dry, deep water and snow road holding are not exactly compatible. A-arm or wishbone front suspension tends to give better handling, because it provides the engineers more freedom to choose the geometry, and more road holding, because the camber is better suited to radial tires, than MacPherson strut, but it takes more space. An inboard braking system is an automobile technology where the brakes are not located in the wheels, as is common today, but instead near the differential. ... A cars handling is a description of the way the car performs, particularly during cornering. ... This article or section does not cite its references or sources. ... A simple MacPherson strut suspension on the left front wheel of a rear-wheel drive vehicle. ...


The older Live axle rear suspension technology, familiar from the Ford Model T, is still widely used in most sport utility vehicles and trucks. The live axle suspension is still used in some sports cars, like the Ford Mustang, and is better for drag racing, but generally has problems with grip on bumpy corners, and stability at high speeds on bumpy straights. Having said that a good live axle can be superior to a poor Independent rear suspension system, in most circumstances. A live axle is a type of beam axle suspension system that uses the driveshafts that transmit power to the wheels to connect the wheels laterally so that they move together as a unit. ... The Ford Model T (colloquially known as the Tin Lizzie and the Flivver) was an automobile produced by Henry Fords Ford Motor Company from 1908 through 1927. ... An Independent Suspension is an automobile suspension system that allows the wheels on an axle to move independent of each other. ...


Aftermarket modifications and adjustments to affect handling

Main article: Racing setup

Lowering the center of gravity will always help the handling (as well as reduce the chance of roll-over). This can be done to some extent by using plastic windows (or none) and light roof, hood (bonnet) and boot (trunk) lid materials, by reducing the ground clearance, etc. Increasing the track with "reversed" wheels will have a similar effect, but remember that the wider the car the less spare room it has on the road and the farther you may have to swerve to miss an obstacle. Stiffer springs and/or shocks, both front and rear, will generally improve handling, at the expense of comfort on small bumps. Performance suspension kits are available. Light alloy (mostly aluminum or magnesium) wheels improve handling as well as ride comfort. Aftermarket is an umbrella term for the collective network of vendors who design and sell vehicular components that are intended to replace the stock manufacturers parts in order to alter the appearance or performance of the vehicle. ... In auto racing, the racing setup or car setup is the set of adjustments made to the vehicle in order to optimize its behaviour (performance, handling, reliability, etc. ...


Moment of inertia can be reduced by using lighter bumpers and wings (fenders), or none at all.

Component Reduce Under-steer Reduce Over-steer
Weight distribution center of gravity towards rear center of gravity towards front
Front shock absorber softer stiffer
Rear shock absorber stiffer softer
Front sway bar softer stiffer
Rear sway bar stiffer softer
Front tire selection1 larger contact area² smaller contact area
Rear tire selection smaller contact area larger contact area²
Front wheel rim width or diameter larger² smaller
Rear wheel rim width or diameter smaller larger²
Front tire pressure higher pressure lower pressure
Rear tire pressure lower pressure higher pressure
Front wheel camber increase negative camber reduce negative camber
Rear wheel camber reduce negative camber increase negative camber
Rear spoiler smaller larger
Front height (because these usually
  affect camber and roll resistance)
lower front end raise front end
Rear height raise rear end lower rear end
Front toe in decrease increase
Rear toe in decrease increase
1) tire contact area can be increased by using wider tires, or tires with fewer grooves in the tread pattern. Of course fewer grooves has the opposite effect in wet weather or other poor road conditions.

2) These also improve road holding, under most conditions. This article or section may contain original research or unverified claims. ... Gasfilled Shock absorber. ... sway bar (also stabilizer bar, anti-sway bar, roll bar, or anti-roll bar, ARB) is an automobile suspension device. ... Firestone tire This article is about pneumatic tires. ... Contact patch is the name applied to the area of a vehicles tire that is in contact with the road surface. ... A wheel with a negative camber angle Camber angle is the angle made by the wheel of an automobile; specifically, it is the angle between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or rear. ... This Ford F-150 pickup truck has two spoilers one on the roof and another on the tailgate. ... Toe is the symmetric angle that each wheel makes with the longitudinal axis of the vehicle, as a function of static geometry, and kinematic and compliant effects. ...

Cars with unusual handling problems

Certain vehicles can be involved in a disproportionate share of single-vehicle accidents - their handling characteristics may play a role: This article or section does not cite its references or sources. ...

  • early Porsche 911s — suffered from treacherous lift off oversteer (where the car unpredictably leaves the road tail first); also the inside front wheel leaves the road during hard cornering on dry pavement, causing increasing understeer. The roll bar stiffness at the front is set to compensate for the rear-heaviness and gives neutral handling in ordinary driving. This compensation starts to give out when the wheel lifts. A skilled driver can use the 911's other features to his/her advantage, making the 911 an extremely capable sports car in expert hands. Later 911s have had increasingly sophisticated rear suspensions and larger rear tires, eliminating these problems.
  • Triumph TR2, and TR3 — began to oversteer more suddenly when their inside rear wheel lifted.
  • Volkswagen Beetle — (original Beetle) senstitivity to crosswinds, due to the lightness of the front of the rear engine car; and poor roll stability due to the swing axle suspension. People who drove them hard fitted reversed wheels and bigger rear tires and rims to ameliorate.
  • Chevrolet Corvair - cited for dangerous handling in Unsafe at Any Speed caused by poor roll stability due to the swing axle rear suspension similar to that used in the Volkswagen Beetle. These problems were corrected with the redesign of the Corvair for 1965, however, it died from its negative publicity.
  • The large, rear-engine Tatra (known as the 'Czech secret weapon') killed so many Nazi officers during World War II that the German Army eventually forbade it's officers from driving the Tatra.
  • Some 1950s American "full size" cars responded very slowly to steering changes, because of their very large angular inertia, softly tuned suspension which made ride quality a priority over cornering, and comfort oriented cross bias tires. Auto Motor und Sport reported on one of these that they lacked the courage to test it for top speed, probably due to their familiarity with smaller European cars and their unfamiliarity with large American cars.
  • Dodge Omni and Plymouth Horizon — these early American responses to the Volkswagen Rabbit were found "Unacceptable" in their initial testing by Consumer Reports, due to an observed tendency to display an uncontrollable oscillating yaw from side to side under certain steering inputs. While Chrysler's denials of this behaviour were countered by a persistent trickle of independent reports of this behaviour, production of the cars was altered to equip them with both a lighter weight steering wheel and a steering damper, and no further reports of this problem were heard.
  • The Suzuki Samurai — was similarly reported by Consumer Reports to exhibit a propensity to tipping over onto two wheels, to the point where they were afraid to continue testing the vehicle without the attachment of outrigger wheels to catch it from completely rolling over; once again, they rated it as "Unacceptable", and once again the manufacturer denied that it was any sort of problem "in the real world", while reports by owners who had experienced such rollovers steadily trickled in. The vehicle was eventually taken off the market before any changes were made to the handling. As SUVs became popular, however, it became evident that their high center of mass made them more likely to tip over than passenger cars, and some even did so during Consumer Reports' testing; but none other than the Samurai showed such a readiness to roll over that they were rated unacceptable, as theoretically predictable by the Samurai's being exceptionally short and narrow. See http://www.safercar.gov/Rollover.
  • Mercedes-Benz A-Class — a tall car with a high center of gravity; early models showed excessive body roll during sharp swerving manoeuvres and rolled over, most particularly during the Swedish moose test. This was later corrected using Electronic Stability Control and retrofitted at great expense to earlier cars.
  • Ford Explorer — a dangerous tendency to blow a rear tire and flip over. Ford had constructed a vehicle with a high center of gravity - the tendency to roll over on sharp changes in direction is built in to the vehicle. Ford attempted to counteract the forces of nature by specifying lower than optimum pressures, in the tires in order to induce them to lose traction and slide under sideways forces rather than to grip and force the vehicle to roll over. For reasons that were never entirely clear, these vehicles then suffered from sudden tire blow outs, which led to a spate of well publicized single-vehicle accidents.
Ford and Firestone, the makers of the tires, pointed fingers at each other, with the final blame being assigned to quality control practices at a Firestone plant which was undergoing a strike. tires from a different Firestone plant were not associated with this problem. An internal document dated 1989 states
Engineering has recommended use of tire pressures below maximum allowable inflation levels for all UN46 tires. As described previously, the reduced tire pressures increase understeer and reduce maximum cornering capacity (both 'stabilising' influences). This practice has been used routinely in heavy duty pick-up truck and car station wagon applications to assure adequate understeer under all loading conditions. Nissan (Pathfinder), Toyota, Chevrolet, and Dodge also reduce tire pressures for selected applications. While we cannot be sure of their reasons, similarities in vehicle loading suggest that maintaining a minimal level of understeer under rear-loaded conditions may be the compelling factor. http://www.citizen.org/autosafety/articles.cfm?ID=5336
This contributed to build-up of heat and tire deterioration under sustained high speed use, and eventual failure of the most highly stressed tire. Of course, the possibility that slightly substandard tire construction and slightly higher than average tire stress, neither of which would be problematic in themselves, would in combination result in tire failure is quite likely. The controversy continues without unequivocal conclusions, but it also brought public attention to a generally high incidence of rollover accidents involving SUVs, which the manufacturers continue to address in various ways.

(One of the handling advantages of sports cars is that their very lack of carrying capacity allows their standard tire pressures, as well as sizes, to be optimised for light load.) Porsche 911 in hillclimb The Porsche 912 (pronounced as nine eleven) is a sports car made by Porsche AG of Stuttgart, Germany. ... Lift-off oversteer (also known as trailing-throttle oversteer, lift-throttle oversteer, or drop-throttle oversteer) is a form of oversteer in an automobile that occurs when the vertical load on the tires shifts from the rear to the front quickly due to throttle release while cornering. ... sway bar (also stabilizer bar, anti-sway bar, roll bar, or anti-roll bar, ARB) is an automobile suspension device. ... Triumph TR2 The Triumph TR3B was produced by the Triumph Motor Company (Standard Motor Company) in 1962. ... This article is about the original Volkswagen Beetle. ... In Automobile design, an RR, or Rear-engine, Rear wheel drive, layout places both the engine and drive wheels at the rear of the vehicle. ... A swing axle is a simple type of independent suspension first used in early 20C. aircraft, Sopwith, Fokker et al, 1910 or earlier usually with rubber bungee and no damping. ... Corvair convertible The Chevrolet Corvair was an automobile produced by the Chevrolet division of General Motors from 1960 to 1969. ... Exhibit featuring the book at Henry Ford Museum, Detroit Unsafe at Any Speed: The Designed-In Dangers of the American Automobile by Ralph Nader, published in 1965, is a book detailing his claims of resistance by car manufacturers to the introduction of safety features, like seat belts, and their general... A swing axle is a simple type of independent suspension first used in early 20C. aircraft, Sopwith, Fokker et al, 1910 or earlier usually with rubber bungee and no damping. ... In automobile design, a rear-engine design layout places both the engine and drive wheels at the rear of the vehicle. ... Tatra is a vehicle manufacturer in KopÅ™ivnice, Czech Republic. ... National Socialism redirects here. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... Plymouth Horizon The Dodge Omni and the similar Plymouth Horizon were front wheel drive subcompact cars introduced by the Dodge and Plymouth divisions of Chrysler Corporation in North America in 1978. ... The Dodge Omni and similar Plymouth Horizon was a front-drive, subcompact car introduced by the Dodge and Plymouth divisions of Chrysler Corporation in North America in 1978. ... VW Golf Mk. ... Consumer Reports is an American magazine published monthly by Consumers Union. ... The word yaw can refer to: Yaw, the name for the Levantine god of chaos, rivers, the sea, and tempests; Yaw, an aeronautical and nautical term which indicates how far a craft is pointing away from its direction of travel due to rotation about its vertical axis. ... For other uses, including the Chrysler Brand, see Chrysler (disambiguation). ... The SJ413, known as the Suzuki Samurai in North America, was an updated version of the SJ410. ... Consumer Reports is an American magazine published monthly by Consumers Union. ... This article or section may be confusing or unclear for some readers, and should be edited to rectify this. ... 2004 Mercedes-Benz W169 A200 The Mercedes-Benz A-Class (popularly known in the U.S. as the Baby Benz) is a small family car produced by the German automaker Mercedes-Benz. ... The Moose test, also known as the Elk test or Älgtest in Swedish, has been used in Sweden for decades to test how a certain vehicle acts when avoiding a sudden danger, such as an elk. ... Electronic Stability Control (ESC) is the generic term for systems designed to improve a vehicles handling, particularly at the limits where the driver might lose control of the vehicle. ... The Ford Explorer is a mid-size sport utility vehicle sold in North America and built by the Ford Motor Company since 1990. ... This article or section does not cite its references or sources. ... The Firestone Tire and Rubber Company was founded by Harvey Firestone in 1900 to supply pneumatic tires for wagons, buggies, and other forms of wheeled transportation common in the era. ... Year 1989 (MCMLXXXIX) was a common year starting on Sunday (link displays 1989 Gregorian calendar). ... Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... 1963 Jaguar E-Type, a classic sports car 1963 Chevrolet Corvette was based upon European sports cars A sports car is an automobile designed for performance driving. ...

  • The Jensen GT (hatchback coupe) — was introduced in attempt to broaden the sales base of the Jensen Healey, which had up to that time been a roadster or convertible. Its road test report in Motor Magazine and a very similar one, soon after, in Road & Track concluded that it was no longer fun enough to drive to be worth that much money. They blamed it on minor suspension changes. Much more likely, the change in weight distribution was at fault. The Jensen Healey was a rather low and wide fairly expensive sports car, but the specifications of its suspension were not particularly impressive, having a solid rear axle. Unlike the AC Ace, with its double transverse leaf rear suspension and aluminium body, the Jensen Healey could not stand the weight of that high up metal and glass and still earn a premium price for its handling. The changes also included a cast iron exhaust manifold replacing the aluminium one, probably to partly balance the high and far back weight of the top. The car had also suffered reliability problems with engines that Jensen bought from Lotus. The factory building was used to build multi-tub truck frames.

1938 Jensen 3. ... 1973 Jensen-Healey. ... Road & Track is an automobile enthusiast magazine in the United States, founded by two friends in 1947. ... 1973 Jensen-Healey. ... A.C. Royal Roadster 1924 A.C. 16/70 Sports Drophead Coupé 1935 A.C. ACE 2-Seater Sports A.C. Greyhound Saloon 1962 1999 Cobra Replica 1971 AC Frua AC Cars Group Ltd. ... 1973 Jensen-Healey. ... Lotus Logo with monogram of its founder, Anthony Colin Bruce Chapman Lotus Cars is a British manufacturer of sports and racing cars based at Hethel, Norfolk, England. ... The Renault Dauphine was an automobile produced by the French manufacturer Renault from 1956 to 1962. ... A sobriquet is a nickname or a fancy name, usually a familiar name given by others as distinct from a pseudonym assumed as a disguise, but a nickname which is familiar enough such that it can be used in place of a real name without the need of explanation. ...

See also

For other uses, see Driving (disambiguation). ... 1963 Jaguar E-Type, a classic sports car 1963 Chevrolet Corvette was based upon European sports cars A sports car is an automobile designed for performance driving. ... Mechanical Engineering is an engineering discipline that involves the application of principles of physics for analysis, design, manufacturing, and maintenance of mechanical systems. ... Car safety is the avoidance of car accidents or the minimization of harmful effects of accidents, in particular as pertaining to human life and health. ... A Peugeot 206 World Rally Car Motor racing and Motorsports redirect here. ... Automotive suspension design is an aspect of automotive engineering, concerned with designing the suspension for cars and trucks. ...

References

Auto racing (also known as automobile racing or autosport) is a sport involving racing automobiles. ... Motor is an Australian motoring magazine published monthly by ACP Magazines. ... Road & Track is an automobile enthusiast magazine in the United States, founded by two friends in 1947. ... Cover of Car and Driver from age of psychedelic lettering Car and Driver is an American automotive enthusiast magazine. ...

External links


  Results from FactBites:
 
America's Best Handling Car - Motor Trend (953 words)
Today's worst-handling car is probably as agile on its well-shod feet as some of the most exotic mid-century sports cars were, and sorting out the crme-de-l'handling-crme now takes more than the simple biological assometer.
To shed some meaningful light on the topic of dynamic handling, we decided to invite top-handling cars representing the four major driveline layouts-front engine, front drive; front engine, rear drive; front engine, all-wheel drive; and mid- or rear engine.
The bulldog Mini Cooper S John Cooper Works GP ($31,150) and the Mitsubishi Evolution IX MR ($37,424) test cars are both 2006 models because their successors weren't yet available, and we couldn't bear to let either of these two staff favorites sit out the competition.
Car handling: Information from Answers.com (4935 words)
Car handling and vehicle handling is a description of the way wheeled vehicles perform transverse to their direction of motion, particularly during cornering and swerving.
In the case of pure racing cars, this is typically between "45/55" and "40/60." This gives the front tyres an advantage in overcoming the car's moment of inertia (yaw angular inertia), thus reducing corner-entry understeer.
The effect of braking on handling is complicated by load transfer, which is proportional to the (negative) acceleration times the ratio of the centre of gravity height to the wheelbase.
  More results at FactBites »

 
 

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